Waugh, T. (1996). Hard to imagine: Gay male eroticism in photography and film from their beginnings to Stonewall. Columbia University.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Waugh, Thomas. Hard to Imagine: Gay Male Eroticism in Photography and Film from Their Beginnings to Stonewall. New York: Columbia University, 1996.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Waugh, Thomas. Hard to Imagine: Gay Male Eroticism in Photography and Film from Their Beginnings to Stonewall. Columbia University, 1996.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.